Process for breaking petroleum emulsions



Patented Apr. 16, 1934 PROCESS FOR BREAKING PETRGLEUM EMULSIONS Melvin De Groote, St. Louis, and Bernhard Keiser, Webster Groves, M0., assignors to Tretolite Gompany, Webster Groves, Mo., a corporation of Missouri N Drawing Application September 16, 1933,

Serial No. 689,798

16 Claims. ((31. 196-4) This invention relates to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the Water.

novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil type, to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state or subjected to other equivalent separatory procedure.

The treating agent or demulsifying agent used in our process consists of an ester of a fatty acid or modified fatty acid, in which the carboxylic hydrogen has been replaced by a sulfonated aromatic residue. Fatty acids are well known demulsifying agents for water-in-oil emulsions, and are disclosed in U. S. Patent No. 1,223,659, dated April 24, 1917, to William S. Barnickel. Likewise, modified fatty acids or their salts or esters are well known demulsifying agents for water-in-oil emulsions, and are disclosed in U. S. Patent No. 1,467,831, dated September 11, 1923, to William S. Barnickel. From the standpoint of said U. S. Patent No. 1,467,831, the acidic hydrogen of the modified fatty acid carboxyl may be replaced by a metal or organic radical such as a C3H5 radical.

The expression modified fatty acids is well understood by those skilled in the art of resolving petroleum emulsions of the water-in-oil type, and has been used frequently in the patent literature to designate a certain well known class of materials. For sake of simplicity and brevity only, the following discussion will consider the carboxy-containing fatty acid as typical of acid, salt and ester. Briefly described, modified fatty acids are modifications of fatty acids obtained by chemical reaction on a fatty acid or its equivalent, so as to result in an addition product or substitution product, and they bear a simple genetic relationship to each other or to the parent fatty acid or fatty acid compound from which they were derived. Thus, while modified fatty acids do include the salts of modified fatty acids, they do not include salts of unmodified fatty acids, such as soaps, because a salt of a fatty acid is not an addition product. Likewise, it is not a substitution product, because substitution products in the sense that such term is used in organic chemistry, is applied not to salts, but to undissociable or indifferent compounds. Furthermore, whereas the acid hydrogen involved in salt formation can be replaced only by metals or metal-like groups, that is, elements or radicals which are electro-positive, substitution may replace the hydrogen of organic compounds by a variety of elements and groups which may be electro-negative. Modified fatty acids retain most of the fundamental characteristics of fatty acids themselves, and are generally characterized by the outstanding identifying property of a fatty acid or fat, namely, the ability to stain paper so as to leave a translucent spot, at temperatures above the melting point, and to undergo saponification.

The treating agent or reagent contemplated by our process, includes esters of a specific kind derived from either fatty acids or modified fatty acids. In order to keep the distinction clear between a fatty acid and a modified fatty acid and yet use a term which will be inclusive of both classes, the expression fatty acid body will be used to indicate both classes of materials. A fatty acid is indicated by the formula R.COOH, in which R. is a fatty acid radical, such as an oleic acid radical, stearic acid radical, palmitic acid radical, ricinoleic acid radical, and COOH indicates the conventional carboxyl radical. If the fatty acid is of the unsaturated type, such as oleic acid, ricinoleic acid, etc., and one produces an addition product by means of a chemical reagent, then the modified fatty acid thus obtained may be indicated by the formula R.XX.COOH, in which XX represents atoms or radicals joined in addition such as OH, HSO4, HSOs, Cl, Br, CSH/IHSQB, etc. XX may represent the same atoms as in the case of oleic acid dichloride, or XX may represent an atom and a radical, as in the case of oleic acid hydrogen hydrogen sulphate. In event that the fatty acid contained more than one ethylene linkage, such as linoleic acid, then one might obtain a modified fatty acid of the type R.XX.XX.COOH, but which is simply considered as a variety of the R.XX.COOH specie.

Just as the fatty acid of the type R.COOII may yield addition products, likewise, it may yield substitution products, and such a modified fatty acid may be designated by the formula RD.COOI-I, in which R is a fatty acid radical residue, D is the substituent atom or radical such as HSO4, C6H4HSO3, phthalic acid residue, oxalic acid residue, acetic acid residue, phosphoric acid residue, chlorine, etc., or a residue of the type R".COO, in which R indicates another fatty acid radical residue which may be different, or it may be the same as R, as in the case of poly acids such as diricinoleic, triricinoleic, etc., CO0 is a carboxyl residue.

Fatty acids such as ricinoleic acid may yield a modified fatty acid which is both an addition and substitution product. For instance, ricinoleic acid may yield a modified fatty acid which is both an addition and a substitution product and may be indicated by the formula RD.XX.COOI-I, in which the various symbols have the same significance as previously. The formula R.COOI-I includes fatty acids such as oleic acid, ricincleic, stearic acid, etc. The formulas R.XX.COOH, R'D.COOH, and R'D.XX.COOI-I include the conventional modified fatty acids. Fatty acid bodies are selected from the class comprising R.COOH R.XX.COOH RD.COOH RD.XX.COOH,

in which the symbols have their previous significance. The above formulas indicate the simple genetic relationship existing among the members of the class.

The treating agent or reagent employed in our present process is a sulfo aromatic ester of a fatty acid body, that is the ester of either a fatty acid or a modified fatty acid, in which the sulfo aromatic residue has replaced the carboxylic hydrogen of the fatty acid or modified fatty acid. The production of such sulfo aromatic esters may be accomplished in a variety of manners. A number of methods for producing such sulfo aromatic esters are disclosed in U. S. Patent No. 1,916,776, dated July 4, 1933, to Steindorff et a1. Briefly stated, one method involves changing the fatty acid to a fatty acyl chloride, such as oleyl chloride, or hydroxy stearyl chloride, and reacting the same with a hydroxylated solfo aromatic, such as phenol sulfonic acid, cresol sulfonic acid, naphthol sulfonic acid, methyl naphtholsulfonic acid, etc., with the elimination of hydrochloric acid and' the formation of an ester. Another method involves changing the fatty acid into a sodium salt and then reacting the same with a sulfo aromatic compound having a labilie halogen such as sosidum benzyl chloride sulfonate The methods disclosed in saidU. S. Patent No. 1,916,776 are applied to fatty acids, but it is obvious that they are applicable to modified fatty acids of the type previously indicated, or one may produce the sulfo aromatic ester of a fatty acid and subsequently subject this ester to reactions so as to produce a modified fatty acid sulfo aromatic ester.

If a fatty acid is indicated by the formula RCOOI-I then the sulfo aromatic ester may be indicated by the formula R.COO.T.SO3.Z, in which R has the same meaning as previously indicated, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, and Z represents the hydrogen of the sulfonic acid or its equivalent such as a metal atom, 'such as sodium, potassium, ammonium radicaL basic amine radical, calcium, magnesium, etc., Z may be an organic radical such as a C2H5 radical. Corresponding to a sulfo aromatic ester of the fatty acids, one may obtain the sulfo aromatic esters of the modified fatty acids and they may be designated by the following type formulas: R.XX.COO.T.SO3.Z, RD.COO.T.SO3.Z, and R'D.XX.COO.T.SO3.Z, in which the symbols have the same significance as previously. It is to be noted that the radical (T.SO3.Z) in both the sulfo aromatic esters of unmodified and modified fatty acids replaces the carboxylic hydrogen.

Before indicating our preferred reagent cer tain salient facts may be of value in defining the nature of our invention. The above reaction may be used to produce a sulfo aromatic compound of a saturated fatty acid such as stearic acid or palmitic acid. The best known sulfo aromatic fatty compounds are the Twitchell reagents. Such reagents are only obtainable from fatty acids having reactive hydrocarbon chains, as indicated by an attached hydroxy radical, or by an ethylene linkage. Oleic acid may yield a Twitchell reagent, but this is not true of stearic acid. Thus, the reagents contemplated in the present process may illustrate a type of a sulfo aromatic compound derived from a saturated fatty acid. Furthermore, saturated carboxy petroleum acids such as the ordinary naphthenic acid may yield a sulfo aromatic compound, Whereas, naphthenic acids do not ordinarily react to produce a Twitchell type of reagent. Although the reagents of the present process are sulfo aromatic fatty bodies, and although Twitchell reagents are sulfo aromatic fatty bodies, yet the reagents of the present process are clearly distinguished from the Twitchell reagents, in that the sulfo aromatic residue or radical is attached to the fatty hydrocarbon chain through the carboxyl residue in the reagents of the present process, whereas, in the Twitchell reagent the sulfo aromatic radical or residue is attached directly to the fatty radical or fatty hydrocarbon chain and is not attached to the carboxyl radical or carboxyl residue. Finally, the reactions indicated may not only yield sulfonated aromatic esters, but they may also yield sulfonated aliphatic esters of fatty acids.

As pointed out in U. S. Patent No. 1,916,776, previously referred to, these reagents have a great wetting power, and thus presumably are colloidal in character, and are surface active. A great many substances which give colloidal solutions and are hydrophile or lipophile are excellent demulsifying agents for water-in-oil emulsions. However, the list of reagents which are capable of acting as wetting agents, frothing agents, emulsifying agents, etc., has increased to such a marked degree that it includes large '7 classes of materials which are not of any significant value as demulsifying agents.

The treating agent that we prefer to use in practising our process is preferably prepared in the following manner: Four hundred and ninety parts by weight of sodium sulfonate benzyl ester of ricinoleic acid (C1'LH32.0HCOO.CH2C6H4.SO3N&) prepared as described in U. S. Patent N0. 1,916,776, previously referred to, is reacted with 148 parts by weight of phthalic anhydride, so as to produce the sodium sulfo benzyl ester of phthaloricinoleic acid, which may be indicated by the following formula:

The reaction is readily carried out by mixing the two reagents in the proportion indicated, and then adding an equal amount by weight of an inert solvent such as xylene, which permits the two active ingredients to react with each other while being stirred constantly at a temperature of approximately 120 to 130 C. The course of reaction can readily be followed by titration of a sample which indicates the disappearance of part of the acidity of phthalic anhydride. Such reaction may take place in less than an hour, but in any event should be completed within four to six hours. The xylene may be distilled off when the reaction is completed, or it may remain in the reagent because it is preferred that the reagent be mixed with any suitable solvent prior to use.

It is understood wherever the replaceable hydrogen is present in the reagent, for instance, the replaceable hydrogen of the carboxyl radical of the phthalic acid residue previously mentioned, that said acid hydrogen may be replaced by any of the customary radicals such as sodium, potassium, ammonium, basic amine radicals, ethyl radicals, methyl radicals, etc. Reagents thus produced will show the widest variety in their solubility. Some may be water soluble, some may be oil soluble, some may be soluble in both water and oil, and some may be substantially insoluble in either oil or water. It appears paradoxical to speak of breaking an oil field emulsion by means of a reagent which is substantially insoluble in either oil or water. On the other hand, it must be remembered that oil field emulsions are frequently broken by the addition of one part of a chemical reagent to 20,000 parts or 30,000 parts of emulsion. Thus, even though a reagent is substantially insoluble in oil and in water, yet it may be sufficiently soluble so that it is entirely dissolved in the minute amount in which it may be used.

The specific form, state, or condition of the treating agent at the time it is used or applied to the emulsion to be treated, is immaterial and may be varied to suit existing conditions. It can be used in substantially anhydrous state or in solutions of any convenient strength. The treating agent may be diluted with any suitable solvent such as ethyl alcohol, methyl alcohol, propyl alcohol, butyl alcohol, kerosene, or any other hydrocarbon solvent, benzol, xylene, solvent naphtha, carbon tetrachloride, pine oil, etc. The treating agent can be employed either alone or in admixture or combination with other well known treating agents for breaking petroleum emulsions of the water-in-oil type, such as water softeners, modified fatty acids, petroleum sulfonic acids, or their salts, etc.

In practising our process, a treating agent or demulsifying agent of the kind above described is brought into contact with the emulsion to be treated in any of the numerous ways now employed in the treatment of petroleum emulsions of the water-in-oil type with chemical demulsifying agents, such, for example, as by introducing the treating agent into the well in which the emulsion is produced, introducing the treating agent into a conduit through which the emulsion is flowing, introducing the treating agent into a tank in which the emulsion is stored, or introducing the treating agent into a container that holds a sludge obtained from the bottom of an oil storage tank. In some instances, it may be advisable to introduce the treating agent into a producing well in such a Way that it will become mixed with water and oil that are emerging from the surrounding strata, before said water and oil enter the barrel of the well pump or the tubing up through which said water and oil flow to the surface of the ground. After treatment the emulsion is allowed to stand in a quiescent state, usually in a settling tank, at a temperature varying from atmospheric temperature to about 200 F., so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough so as to prevent the valuable constituents of the oil from volatilizing. If desired, the treated emulsion may be acted upon by one or the other of various kinds of apparatus now used in the operation of breaking petroleum emulsions, such as homogenizers, hay tanks, gun barrels, filters, centrifuges, or electrical dehydrators.

The amount of treating agent on the anhydrous basis that is required to break the emulsion may vary from approximately 1 part of treating agent to 500 parts of emulsion up to a ratio of 1 part of treating agent to 20,000 parts of emulsion, depending upon the type or kind of emulsion being treated. In treating exceptionally refractory emulsions of the kind commonly referred to as tank bottoms or residual pit oils, the ratio 1 to 500, above referred to, is often necessary, but in treating fresh emulsions, i. e., emulsions that will yield readily to the action of chemical demulsifying agents, the ratio 1 to 20,000 above mentioned, will frequently produce highly satisfactory results. For the average petroleum emulsion of the water-in-oil type a ratio of 1 part of treating agent to 10,000 parts of emulsion will usually be found to produce commercially satisfactory results.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo aromatic ester of a fatty acid body selected from the class consisting of the following types:

in which R is a fatty acid radical, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.S03.Z) replaces the fatty acid carboxylic hydrogen, XX represents atoms or radicals joined in addition, R is a fatty acid radical residue, and D is a substituent atom or radical.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in sub jecting the emulsion to the action of a demulsifying agent containing a monocyclic sulfo aromatic ester of a fatty acid body selected from the class consisting of the following types:

in which R is a fatty acid radical, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, XX represents atoms or radicals joined in addition, R is a fatty acid radical residue, and D is a substituent atom or radical.

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a polycyclic sulfo aromatic ester of a fatty acid body selected from the class consisting of the following types:

; in which R is a fatty acid radical, C00 is the oarboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, XX represents atoms or radicals joined in addition, R is a fatty acid radical residue and D is a substituent atom or radical.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in sub jecting the emulsion to the action of a demulsifying agent containing a sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical, XX represents atoms or radicals joined in addition, CO0 is the carboxyl residue, T is the aromatic residue, SOs is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, R is a fatty acid radical residue, and D is a substituent atom or radical.

5. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a monocyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical, XX represents atoms or radicals joined in addition, 000 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, R is a fatty acid radical residue, and D is a substituent atom or radical.

6. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a polycyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical, XX represents atoms or radicals joined in addition, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces thefatty acid carboxylic hydrogen, R is a fatty acid radical residue, and D is a substituent atom or radical.

'7. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical residue, D is a substituent dibasic carboxy acid residue, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

8. A process for breaking petroletun emulsions of the Water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a monocyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

jecting the emulsion to the action of a demulsifying agent containing a polycyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical residue, D is a substituent dibasio carboXy acid residue, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition. 7

10. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical residue, D is a substituent phthalic acid residue, 000 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

11. A process for breaking petroleum emulsions of the water-in-oil type, which consists in sub jecting the emulsion to the action of a demulsifying agent containing a monocyclio sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R, is a fatty acid radical residue, D is a substituent phthalic acid residue, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

12. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a polycyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R. is a fatty acid radical residue, D is a substituent phthalic acid residue, 000 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

13. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

R'D.COO (T.SO3.Z) R'D.XX.COO (T5032) in which R is a fatty acid radical residue derived from castor oil, D is a phthalic acid residue,

C00 is the carboxyl residue, T is the aromatic acid or its equivalent, thus (T5031) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

14. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a monocyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical residue derived from castor oil, D is a substituent phthalic acid residue, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

15. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a polycyclic sulfo aromatic ester of a modified fatty acid selected from the class consisting of the following types:

in which R is a fatty acid radical residue derived from castor oil, D, is a substituent phthalic acid residue, CO0 is the carboxyl residue, T is the aromatic residue, S03 is the conventional sulfonic acid residue, Z represents the hydrogen of the sulfonic acid or its equivalent, thus (T.SO3.Z) replaces the fatty acid carboxylic hydrogen, and XX represents atoms or radicals joined in addition.

16. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing the sodium sulfo benzyl ester of phthalo-ricinoleic acid.

MELVIN DE GROOTE. BERNHARD KEISER. 

